The objective of this study was to evaluate the relationship between variations of the lateral wall of the nasal cavity and septal deviation (SD). Coronal and axial paranasal sinus CT images of 115 individuals (65 females, 50 males) were reviewed and the presence of pneumatisation and hypertrophy of the conchae was evaluated. Pneumatisation of the concha was classified as lamellar concha bullosa (LCB), bulbous concha bullosa (BCB), or extensive concha bullosa (ECB). If bulbous and extensive conchae and hypertrophic conchae were bilateral the side on which it was greatest was accepted as the dominant concha. The relationship between these variations and nasal septum deviation was also taken into account. Eighty-six (74.8%) of the 115 subjects had SD. Of these, 20 were not affected by the size of the middle nasal concha (MNC) or inferior nasal concha (INC). Thirty-four cases had dominant MNC, 20 had dominant INC, and 11 had both dominant MNC and dominant INC, and all of which had SD towards the opposite side. In one case there was SD towards the side in which the MNC was dominant. Our data indicate that coexistence of pneumatisation or hypertrophy of the conchae and SD was more common in adults compared to the results of similar studies conducted with a wide range of age groups, including children. Thus the presence of SD together with a large concha increases with age. A prospective study, which will include infants, will elucidate the relationship between conchae and SD.